Objective: to compare the pharyngeal airway dimensions among cleft lip and palate patients and non-cleft lip and palate patients by using Cone-beam computed tomography (CBCT). Material and methods: The sample included 60 cone-beam computed tomography (CBCT) of patients both males and females with age range 8-12 years, 30 patients with cleft lip and palate and 30 patients with non-cleft lip and palate. Measurements including Oropharnx linear measurment (width and depth), Nasopharynx linear measurment (width and depth) and Volumetric analysis( oropharynx and nasopharynx) were made digitally on 3-dimensional based dental software (In Vivo Dental, Anatomage, San Jose, CA, USA). Results: For all cases including males and females, results showed statistically significant differences between control and cleft groups in oropharynx measurements (depth and volume) and in nasopharynx width.. 10 patient CBCT records in cleft and control groups were randomly selected and all measurements were repeated to test intraexaminer and interexaminer reliability respectively. For reliability evaluation results showed excellent agreement between measurements at two different time intervals. Conclusion: Oropharyngeal airway space (depth-width and volume) and nasopharyngeal (width). significantly decreased in cleft than control patient.